Medical treatments for the shortcomings or functional deficiencies of biological organs and systems have long included the implantation of inorganic medical devices or the implantation of medical devices that are formed, at least in part, of inorganic materials. Such medical devices are designed to restore or replace a useful biological function needed by the host animal. Implantable medical devices have been designed to perform a variety of biological functions, including, without limitation, restoring the functioning of a failed heart, monitoring the chemical or electrical stimuli produced by a system or organ, secreting needed synthetic pharmaceutical compositions, and draining undesirable fluids from organs or tissues. Implantable devices such as catheters, stents, fluid flow control valves, biosensors, pressure sensors, pacemakers and the like are well known in the medical industry.
The implantation of such device for long periods of time, that is, on the order of months or years, has often proven unsuccessful due to rejection by the immunological system of the host animal, particularly as a result of fibrous tissue growth. Fibrous tissue growth can impair the operation of certain devices such as, for example, sensors. Fibrous tissue growth can also reduce the efficiency of devices such as electrodes in pacing devices and antennas in in-vivo telemetry systems.
Current solutions for the prevention of fibrous tissue growth on implanted devices have included the use of timed releasable drugs or molecules, such as heparin or other antibiotics and antithrombogenics. However, such methods typically have proven to be short-term solutions, that is, on the order of days to months. In addition, the use of such drugs is costly, may have deleterious effects on the immune system of the host animal, and may subject the host animal to the side effects of the drugs.
Accordingly, a need exists for a medical device suitable for long-term implantation in a host animal. A need also exists for a process for fabricating a medical device suitable for long-term implantation in a host animal.
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